Isolation circuits are for data and/or power transfer across a galvanic isolation barrier to interconnect electrical systems powered by different supply sources that do not share a common ground connection. Transformer isolation approaches involve switching circuits and magnetic fields, and the resulting electromagnetic interference (EMI) may be undesirable in certain applications. In addition, transformer isolation typically requires an additional transformer component and these solutions require significant circuit area and are costly. Capacitive coupling or AC coupling can be used to provide isolation for data transmission, but capacitor-based isolation solutions often involve parasitic capacitance that absorbs signal energy and leads to poor power efficiency. In addition, high voltage breakdown voltage ratings are costly to implement using capacitive coupling due to the need for thick layers of surface dielectric. Optical isolation avoids the EMI and circuit area problems associated with transformer isolation by transferring electrical power/signals between galvanically isolated circuits using light via a photon emitter (e.g., a light-emitting diode or LED), a receiver or sensor such as a Photo-Voltaic diode (PVD) and an optical coupling material. Optical coupling devices or optocouplers typically stack an LED source above a PV diode with glass or other transparent material in between to transmit photon energy vertically downward to the top of the PVD sensor. Moreover, high breakdown voltage isolation ratings can be achieved only by increasing the distance between the LED and the PVD, resulting in sometimes unacceptable vertical device heights. Some high isolation voltage optocouplers use a reflective dome that reflects light from the LED to the photodiode, which are positioned side-by-side for upward transmission by the LED and downward reception by the photodiode. In these conventional optocoupler approaches, the photon path is perpendicular to the surface of the silicon devices. LED light sources typically provide light signals at or near infrared wavelengths, and optocouplers generally suffer from poor power efficiency (e.g., current transfer ratio or CTR representing the ratio of the input current to the output current). In addition Common Mode Transient Isolation (CMTI) suffers in vertical constructions due to the capacitive coupling between emitter and detector. Accordingly, conventional optical isolation techniques do not provide adequate solutions for many power transfer applications.